I think Fairy encompasses beings of light and goodness well enough.
Should they make Light Screen a Light move? I don't know.
I think the fact that they've only introduced one type since GSC is a good thing. There are already too many types. That's why several types (Poison, Psychic, Grass, Bug) are often pushed to borderline irrelevance.
So it's SE against Dark and Dark is SE against it? That doesn't seem right. Overall, I don't really like the idea of the light type, doesn't solve any apparent problems. --- 3DS Name: Deadpool FC: 5429-7982-0261 TSV: 1775 BR-ALL-AR